Early detection of disease is often an important factor in effective treatment. As such, screening for disease prior to the onset of outward symptoms has become routine practice for certain diseases, such as breast cancer and newborn metabolic disorders. Given that these and other screening practices have become successful, development of new and different types of screening tests applicable to varied types of disorders is ongoing in the medical research community. While most diagnostic and screening methods rely on detecting specific physiological or biochemical markers, recent research has shown the effectiveness of detecting disease by determining a profile of biochemical markers from a patient sample. This is possible because molecules contained in a patient sample can reflect a physiological state of the patient's body at the time of sample collection.
Peptide and protein biomarkers are emerging as indicators of the physiological state of biological systems, and therefore as diagnostic and prognostic markers. Recent developments in proteomics-based technologies have allowed analysis of complex protein samples and have thereby enabled biomarker profiling of tissues and biological fluids. An important aspect of biomarker profiling using these methods is sample preparation. How a specimen is prepared for analysis can determine the quality of a biomarker profile because these peptides are generally present in low concentrations relative to other proteins contained in biological specimens. Moreover, biological specimens generally contain certain proteins in high abundance, such as albumin in blood. It has been observed that high abundance proteins such as albumin often bind to peptides in the body, serving as carriers for these peptides. The particular peptides bound to high abundance proteins can be indicators of the physiological state of the patient, and therefore can serve as biomarkers. Thus, the ability to prepare samples containing peptides would facilitate discovery of biomarkers as well as development of clinical tests using biomarkers.